Mercury,arsenic and cadmium in the unfried and fried fish

Determination of mercury, arsenic and cadmium in unfried and fried fish samples has been carried out by neutron activation followed by chemical separation to remove the interfering activities of copper, zinc etc. This paper presents results of finding on losses of mercury, arsenic and cadmium in the unfried and fried fish.     

Proteomic characterization of human platelet-derived microparticles

Microparticles (MPs) are small fragments of apoptotic or activated cells that may contribute to pathological processes in many diseases. Platelet-derived MPs (PMPs) are the most abundant type of MPs in human blood. To characterize the proteins in PMPs we used a shotgun proteomics approach by nanoHPLC separation followed by MS analysis on an LTQ Orbitrap XL. PMPs were produced from isolated platelets stimulated with adenosine diphosphate (ADP). We developed an analytical platform constituted by two different steps: in the first one we used a standard shotgun strategy; in the second one, to improve low-molecular weight, low-abundance-proteins identification, the samples were fractionated using hydrogel nanoparticles, an enrichment system based on a mixed mechanism of dimensional exclusion and colorant affinity. This was chosen to tackle a common issue with shotgun approaches, in which the low-abundance proteins are not detected when surveys are on a broad scale. By means of the entire analytical platform, we identified 603 proteins, 243 of which were not previously identified. A simple and straightforward procedure for the study of PMPs was provided, producing a tool for further understanding their biological and pathological roles, and a baseline for future studies aimed at discovering biomarkers involved in several diseases.     

Determination of mercury,arsenic and cadmium in fish by neutron activation

Determination of mercury, arsenic and cadmium in fish has been carried out by neutron activation followed by chemical separation to remove the interfering activities of copper, zinc, etc. Some of the common varieties of fish have been analysed and their results are presented.     

Proteomic characterization of early-stage differentiation of mouse embryonic stem cells into neural cells induced by all-trans retinoic acid in vitro

Embryonic stem (ES) cells are totipotent stem cells, which can differentiate into various kinds of cell types, including neurons. They are widely used as a model system for investigating mechanisms of differentiation events during early mouse development. In this study, proteomic techniques were used to approach the protein profile associated with the early-stage differentiation of ES cells into neuronal cells induced by all-trans retinoic acid (ATRA) in vitro. In comparison of the protein profile of parent ES cells with that of ES-derived neural-committed cells, which was induced by ATRA for four days, 24 differentially displayed protein spots were selected from two-dimensional electrophoresis (2-DE) gels for further protein identification by pepide mass fingerprinting (PMF). Nine proteins were known to being involved in the process of neural differentiation and/or neural survival. Of those, alpha-3/alpha-7 tubulin and vimentin were down-regulated, while cytokeratin 8, cytokeratin 18, G1/S-special cyclin D2, follistatin-related protein, NEL protein, platelet-activating factor acetylhydrolase IB alpha-subunit, and thioredoxin peroxidase 2 were upregulated during differentiation of ES cells to neural cells. Additionally, other 12 protein (five upregulated and seven downregulated) spots associated with ES cell differentiation into neuronal cells were not matched to known proteins so far, implicating that they might be novel proteins. The results above indicated that the molecular mechanisms of differentiation of ES cells to neural cells in vitro might be similar to those of other neural systems in vitro and identified that proteomic analysis is an effective strategy to comprehensively unravel the regulatory network of differentiation.     

Proteomic strategies for rapid characterization of micro-organisms

Bioinformatic considerations are offered to illustrate strengths and limitations of the characterization of Bacillus spores based on proteomic interpretation of matrix-assisted laser desorption/ionization spectra. In particular, species-specific biomarkers are evaluated in the context of both experimental access and uniqueness in silico.     

砷镉复合污染稻田修复研究进展

我国农田土壤重金属污染严重,其中稻田土壤砷镉(As/Cd)复合污染形势严峻。相较于其他粮食作物,水稻具有更强的积累As/Cd能力,稻米中As/Cd通过食物链进入人体会对人类健康带来危害。因此,修复As/Cd复合污染稻田土壤,降低稻米As/Cd含量,对保障我国粮食安全生产意义重大。本文综述农田As/Cd复合污染现状及危害,讨论了As/Cd有效性影响因素及水稻中As/Cd吸收转运机制,详细探讨了稻田中As/Cd污染的修复方法。最后针对目前修复技术提出存在的不足和展望,以期为As/Cd复合污染稻田土壤修复提供一定的指导。     

Lead,cadmium, and arsenic in commercial algae of the Sea of Japan

The concentrations of toxic elements (arsenic, cadmium, lead) in commercial algae Saccharina japonica and Ahnfeltia tobuchiensis from different habitats of the Sea of Japan have been determined. Bioaccumulation of heavy metals has been analyzed with respect to the habitat and growth conditions. The lead content of Sascharina japonica from all habitats and arsenic content of the same alga species from the Ol’ga Bay, Kievka Bay, and Tatar Strait have been found to exceed maximum permissible levels. Increased lead concentrations have been detected in Ahnfeltia tobuchiensis. Samples of Ahnfeltia tobuchiensis collected from the bottom layer contain more toxic elements than those from the upper layer.     

Proteomic analysis of simulated occupational jet fuel exposure in the lung

We analyzed protein expression in the cytosolic fraction prepared from whole lung tissue in male Swiss-Webster mice exposed 1 h/day for seven days to aerosolized JP-8 jet fuel at concentrations of 1000 and 2500 mg/m3, simulating military occupational exposure. Lung cytosol samples were solubilized and separated via large scale, high resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant quantitative and qualitative changes in tissue cytosol proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass fingerprinting, confirmed by sequence tag analysis, and related to impaired protein synthetic machinery, toxic/metabolic stress and detoxification systems, ultrastructural damage, and functional responses to CO2 handling, acid-base homeostasis and fluid secretion. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression and corroborate previous morphological and biochemical evidence. Further molecular marker development and mechanistic inferences from these observations await proteomic analysis of whole tissue homogenates and other cell compartment, i.e., mitochondria, microsomes, and nuclei of lung and other targets.     

Determination of arsenic,cadmium and zinc in river water by neutron activation analysis

A concentration apparatus has been developed for the determination of As, Cd and Zn in water by neutron activation. The preconcentration technique used for this purpose is based on the retention of As, Cd and Zn on the Rexyn 201 resin at pH 10. The apparatus used minimizes the manipulations needed for preconcentration and contamination by trace elements present in reagents. Eleven samples of water from rivers in the Montreal region were analyzed and the following concentrations were found (in μg/1): As 0.86–1.95, Cd 0.61–0.98 and Zn 4.6–12.9.     

Quality control in integrated human exposure monitoring of lead and cadmium

Summary The Human Exposure Assessment Location, HEAL, Project is implemented by WHO/UNEP in close collaboration with national agencies in different countries. In a first phase methods for exposure monitoring of Pb, Cd, DDT, HCB and NO₂ will be tested in China, Japan, Sweden, USA and Yugoslavia, possibly also Brazil and India. The Pb/Cd study, which involves measurements of lead and cadmium in blood, duplicate diets, feces and inhaled air, collected by a group of non-smoking women in each participating country, is coordinated by a Technical Coordinating Centre (TCC) in Sweden. In order to assure accuracy and comparability of data an extensive quality assurance programme has been developed. Quality control (QC) samples for lead and cadmium in blood, feces, air filters, dust and diets have been prepared. Sets of 4–6 External Quality Control (EQC) samples, the metal concentrations of which are unknown to the laboratories, and 1–2 Internal Quality Control (IQC) samples with stated Pb/Cd-levels, have been distributed. The analytical performance evaluation is based on linear regression analysis of reported results (y) versus reference values (x). Criteria for how much the regression line may deviate (Maximum Accepted Deviation, MAD) from the ideal line (y=x) have been developed. A power of 90% is employed, which means that the actual acceptance interval for the regression line is slightly narrower than the MAD-interval. This procedure gives an estimate of the maximum systematic errors involved in the analysis. The MAD criteria for the evaluation of QC results are based on the data quality requirements as well as the feasibility of the analytical techniques.The results of the first QC rounds show that good analytical performance on one QC sample is no guarantee for good results at higher or lower concentrations or good results with other types of samples. Furthermore, analytical performance may vary with time.

---

Qualitätskontrolle bei der integrierten Überwachung der menschlichen Belastung mit Blei und Cadmium

     

The determination of traces of antimony,tin and arsenic in cadmium by pulse polarography

Traces of antimony, tin and arsenic in cadmium products were determined by pulse polarography. Arsenic was distilled, while antimony and tin were precipitated as hydroxides with manganese dioxide as carrier; some lead was coprecipitated with tin, hence these elements were further separated by distillation. In all cases quantitative recoveries were obtained. Antimony(III) was determined in a hydrochloric acid-sodium hypophosphite mixture, tin(IV) in a hydrochloric-hydrobromic acid mixture and arsenic(III) in sulphuric acid as supporting electrolytes; for arsenic(III), methylene blue had to be added. A sample weight of 10 g and an end volume of 10 ml allowed the determination down to about 0.004 p.p.m. antimony, 0.006 p.p.m. tin and 0.003 p.p.m. arsenic in cadmium. Several synthetic samples and commercially available cadmium products were analysed.     

掺铁羟基磷灰石对铅镉砷的去除性能研究

采用超声-微波水热的方法制备羟基磷灰石过程中添加FeCl3.6H2O,得到对铅（Pb）、镉(Cd)、砷(As) 均具有去除能力的弱晶态掺铁羟基磷灰石（Fe-HAP）材料。通过X射线衍射、Ｘ射线光电子能谱、比表面积分析等研究了Fe-HAP的结构性质,并探究了不同合成工艺下对吸附As(Ⅴ)、Pb2+、Cd2+的影响,并通过设计正交实验对各因素进行分析评估。结果表示：对As(Ⅴ)的去除,最佳掺铁量为40%、pH为9.5、超声-微波时间为15min,最大饱和吸附量为49.4 mg/g;对Pb2+、Cd2+的去除,最佳掺铁量为20%、pH为11、超声功率为200W、超声-微波时间为15min,最大饱和吸附量为1000mg/g、339.3 mg/g。正交试验验证表明Fe/(Fe+Ca)摩尔比是影响材料吸附Pb2+、Cd2+的最主要的因素;而对于吸附As(Ⅴ),合成pH的影响最大。Fe-HAP对Pb2+、Cd2+、As(Ⅴ)的去除归因于吸附-沉淀作用。     

Radiochemical determination of mercury,arsenic, cadmium,zinc and copper in biological materials

Extraction procedure for mercury, arsenic, cadmium, copper and zinc in biological materials is proposed. Mercury and copper are extracted with dithizone followed by the separation of mercury with tri-octyl-amine (TOA). Arsenic, cadmium and zinc are extracted as diethyldithiocarbamates. The procedure is applied for the analysis of some reference materials and autopsy human samples of kidneys, liver, heart, spleen and hair.     

Proteomic characterization of donkey milk “caseome”

At present, compared with bovine milk, the characterization of donkey milk caseins is at a relatively early stage progress, and only limited data are related to its genetic polymorphism. In this work, the heterogeneity of donkey caseome was investigated using a proteomic approach, based on one- (PAGE, UTLIEF) and two-dimensional (PAGE → UTLIEF) electrophoresis, stained with either Coomassie Brilliant Blue or specific polyclonal antibodies, and structural MS analysis. These combined methodologies allowed the contemporary identification of donkey α_s1, α_s2, β and κ-CN with their related heterogeneity due to phosphorylation (α_s1, α_s2 and β-CN), glycosylation (κ-CN) and incorrect splicing of RNA in mRNA (deleted forms of α_s1-CN and β-CN). The results achieved showed 11 components for κ-CN, six phosphorylated components for β and α_s1-CN and three main phosphorylated components for α_s2-CN, each accounting for 10, 11 and 12 P/mole. At this regard, for the first time, the primary structure of the expressed protein corresponding to the only available donkey α_s2-CN cDNA sequence was determined. Furthermore β-CN was found in homozygous and heterozygous state for the occurrence of a genetic β-CN variant having a MW value 28 mass units higher than the common β-CN phenotype.     

Radiochemical neutron activation analysis for arsenic,cadmium, copper and molybdenum in biological matrices

A simple two step radiochemical separation scheme has been developed which permits the RNAA determination of As, Cd, Cu and Mo in biological matrices. The RNAA separation is applied following the INAA determination of at least 17 other elements in the same samples. Under our experimental conditions which included a four day decay period for handling and shipping from a remote reactor site, detection limits for As, Cd, Cu and Mo are 0.24, 6.6, 45 and 3.4 ng, respectively, in NBS biological standard reference materials SRM 1571 and 1567. Decontamination factors for the major spectral interferences,⁸²Br,⁴²K,²⁴Na³²P and¹²²Sb have been determined and found to be sufficiently high for measurement of the elements of interest in most biological matrices. The overall INNA/RNAA procedure takes full advantage of high resolution Ge(Li) gamma-ray spectroscopy and involves minimal chemical processing.     

Synthesis and initial characterization of arsenic (V) polyamines

The interfacial synthesis of arsenic (V) polyamines is presented. Soluble products exhibit weight-average molecular weights of about 10⁵. Steric nature and nucleophilicity

of the diamine do not appear to be critical factors. Base initiated degradation of the product is important. Condensation is “diffusion controlled” to a stirring rate about 11,000 rev/min, thereafter being kinetic controlled. Thermal degradation begins after ca. 200°C occurring via an oxidative mode in air. Stability plateaux are kinetically controlled.     

Proteomic analysis of the renal effects of simulated occupational jet fuel exposure

We analyzed protein expression in the cytosolic fraction prepared from whole kidneys in male Swiss-Webster mice exposed 1 h/day for five days to aerosolized JP-8 jet fuel at a concentration of 1000 mg/m3, simulating military occupational exposure. Kidney cytosol samples were solubilized and separated via large-scale, high-resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant changes in soluble kidney proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass finger-printing and related to ultrastructural abnormalities, altered protein processing, metabolic effects, and paradoxical stress protein/detoxification system responses. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression in the kidney and provide novel molecular evidence of JP-8 nephrotoxicity. Human risk is suggested by these data but conclusive assessment awaits a noninvasive search for biomarkers in JP-8 exposed humans.     

Determination of arsenic, cadmium, lead and selenium in highly mineralized waters by graphite-furnace atomic-absorption spectrometry

A graphite-furnace AAS method using the stabilized-temperature platform furnace (STPF) concept, mixed palladium and magnesium nitrates as chemical modifier and Zeeman background correction has been applied to the direct determination of As, Cd, Pb and Se in highly mineralized waters used for medicinal purposes. These contain 20-40 g/l. concentrations of salts, mainly sodium and magnesium chlorides, bicarbonates and sulphates. The use of a pre-atomization cool-down step to 20 degrees in the graphite-furnace programme reduced the background absorption. Increasing the mass of magnesium nitrate modifier to 5 times that originally proposed improved the analyte peak shape. Under these conditions, no interference was found in analysis of the chloride/bicarbonate type of water, but the sodium and magnesium sulphate type of water had to be diluted, and even then an interference remained. Calibration with matrix-free standard solutions was used, but use of spike recovery is strongly recommended for testing the accuracy. The limits of determination (4.65sigma) of the proposed method for undiluted samples are 2.0 mug/l. for As, 0.05 mug/l. for Cd, 1.0 mug/l. for Pb and 1.5 mug/l. for Se.     

Proficiency testing program for the determination of total arsenic, cadmium, and lead in seawater shrimp

The proficiency testing (PT) program for 97 worldwide laboratories for determining total arsenic, cadmium, and lead in seawater shrimp under the auspices of the Asia-Pacific Laboratory Accreditation Cooperation (APLAC) is discussed. The program is one of the APLAC PT series whose primary purposes are to establish mutual agreement on the equivalence of the operation of APLAC member laboratories and to take corrective actions if testing deficiencies are identified. Pooled data for Cd and Pb were normally distributed with interlaboratory variations of 21.9 and 34.8%, respectively. The corresponding consensus mean values estimated by robust statistics were in good agreement with those obtained in the homogeneity tests. However, a bimodal distribution was observed from the determination of total As, in which 14 out of 74 participants reported much smaller values (0.482-6.4 mg/kg) as compared with the mean values of 60.9 mg/kg in the homogeneity test. The use of consensus mean is known to have significant deviation from the true value in bi- or multimodal distribution. Therefore, the mode value, a better estimate of central tendency, was chosen to assess participants' performance for total As. Estimates of the overall uncertainty from participants varied in this program, and some were recommended to acquire more comprehensive exposure toward important criteria as stipulated in ISO/IEC 17025.